Ki captained South Korea all the way to the final of the AFC Asian Cup, where they were defeated by hosts Australia.
The 26-year-old returned for the Swans this weekend against former club Sunderland after three weeks away on national duty. Ki scored an equaliser on his return and was named man of the match afterwards.
He said: "I didn't know I was going to be South Korea captain so that was a surprise and there was a lot of pressure on the captain. I didn't realise that because I haven't been captain before.
"We were in the final. We couldn't be the champions, but it was a great experience because there are a lot of young players in the team. They know what they have to work on so we can become a better team. I was away from Swansea for so long, so I felt sorry about that.
"I had to come back. On Saturday my body did not feel 100 per cent, but I wanted to win this game, especially against Sunderland who I played for last season."
Ki added: "First of all, we couldn't get the three points so I was a little disappointed because I thought we were in control of the game.
"We had some good chances and we should have scored more than one goal. This kind of game is hard because they didn't get any shots or really have any good chances.
"At the end of the game it's 1-1 so we need to work harder. It was not a special game, but because I was away from Swansea I really tried to focus myself because I know I'm not 100 per cent. I had to concentrate more in the game."